Pliers.



H. V. SMITH.

Patented May 21, 1918.

1,267,w&

WITNESS ATTORNEYS c plication r rice.

HENRY V. SMITH, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR OF CITE-HALF TO"EUGENE H. E. SMITH, F BRIDGEPOBT, CONNECTICUT.

PLIERS.

4 memes.

Specification of Letters Patent.

Patented May 231., 11218..

To all whom it may concern:

Be it known that I, HENRY V. SMITH, a citizen of the United States,residing at Bridgeport, county of Fairfield, State of Connecticut, haveinvented an Improvement in Pliers, of which the following is aspecification. I

This invention relates generally to pliers, and such auxiliaryattachments or appurtenances as may under certain conditions be desiredto or associated therewith or form a part thereof. The invention hasmore par- 7 ticular reference to the manner of pivotally connecting thetwo parts which cotiperate to effect the desired results.

Heretofore, so far as I been the more general practice to provide asingle central pivot, which either acts individually or as a part ofwhat may be termed a pivotal system. In the first case,

it will be apparent that nodifl'erent mechanical action is producedother than that of an ordinary pair of shears. In the second case, theso-called pivotal system is generally designed to insure movement of thegripping jaws in" parallel at a sacrifice of both power and strength.Undoubtedly each form has its advantages, but both are subject toobjections, because'in securing these advantages sacrifices must be madein other directions, as suggested. I have found that through what may betermed a double or divided pivotal connection, I am enabled not only toenhance the applied forces in .pliers of any given size, resulting fromapof manual forces of the same deree, but also to provide a constructionin which the mass of metal at the weak points of the device is notmaterially reduced for the purpose of providing bearings and bearingsurfaces. The provision of a single pivotal point or fulcrum hasundoubtedly been due, first, to an attempt to economize in cost ofproduction, and, second, to a failure to recognize the necessity for adefiniterelationship between leverage and direction of movement. Theprincipal object of the tion is to materi pliers of a given same time-p"includes cuttiy terrace esent invenae power of secure at the the deviceam aware it has of metal at the ordinarily weaker points of the leversand maintain a design which is conventional and therefore more readilymarketable. 4

My invention will be better understood by reference to the accompanyingdrawings, forming a part of this specification in which Figure 1 is aside elevation of a pair of pliers embodying. my invention;

Fig. 2 is a top plan or edge view thereof;

Fig. 3 is a fragmentary elevation of the side of the pliers opposite tothat shown in Fig. 1, with the connectinglink removed;

Fig. 4. is a view of the same with the jaws in an open condition, and

Fig. 5 is a section taken substantially on the line 5-5 of Fig. 1.

Referring now to the drawings in detail, I have shown my pliers ascomprising the usual crossed members 11 and .12, the major portion ofeach thereof constituting an operating lever, '13 and 14, respectively,and the other ends, 15 and 16, providing the gripping jaws, andincluding such other instrumentalities as may be desired, such as thecooperating edged blades 17 17 for severing a strand of wire or thelike.

Instead of being provided with'a 'shigle centrally-located pivot,

of both of the members 11 and 12 with registering recesses or pockets 2626 jointly The two opposite links adapted to receive and 18 areconnected at their ends by means of the pins or rivets 19 and 20 whichpass through holes in the members 11 and 12, respectively, and thus formpivots about which these members may oscillate. 7 Longitudinal movementof these members relative to each other, without interfering withpivotal movement thereof is minimizedand almost wholly prevented-by theinterposition therebetween of what may be termed a roller 23, oppositefaces of the jaws 15 and 16 be ng substantially circularly recessed toreceive and contain this roller which is loosely held in place in saidrecesses by the links 1 53 18 (as shown in Fig. 5). @pening the 32. 16to anextent suf icient to per q 5. roller I I provide each side containa link 18.

mum extent, at the the greatest power;

' have a certain movement about the pivots 21 and 22 relative to thelinks 18, and on this account I so dimension the recesses or pockets 26in these members-for the reception of the link ends as to providesufiicient play or clearance for this relative movement.

It will be apparent, first, as will appear from an inspection of Fig. 4,that if a-single pivot were employed, or the two mem bers have a commoncenter of oscillation, this pivot or center must obviously be located atthe intersection of the crossed memat which the wire or other articlecan be inpp y 85 serted between the jaws a substantial distance forwardof the fulcrum, thus sacrificing power under the well-known principlesof the lever. In the device of my invention, the wire to be cut, or thearticle to be under ordinary conditions be so far inserted between thejaws as to approximate the common plane of the fulthe center of crums.

Furthermore, each of these members rotates about its pivot as a center.Therefore, the point on the face of each jaw at which the article to becut or gripped is located, has relative movement in the arc of a circlethe radius of which is the distance from th pivot to said point. Thisenables me to avail myself, in addition to ordinary leverage, of therelatively great power of the toggle. Theoretically, of course, thesecircles should be tangential, but in practice, of course, it isnecessary to make themintersect. Obviously, the closer the body tobeoperated upon is brought to what may be-termed the dead center-that isto say, to the common plane of the pivotal 7 centersthe greater thepower, and it will be apparent that in the device of my invention a wireor other body of a size such as that in connection with which a deviceof this character is normally designed to be used, may be insertedbetween the open jaws and located for operation at a point whichapproximates the plane of the pivot centers, therebyenabling me to applypower which may almost be said to be limited only by the inherentstrength of the device of the whole.

I might also call attention to the fact that the two cooperating membersof my device are identicaland therefore interchange ablethus effecting amaterial saving in cost of manufacture over constructions whichnecessitate separate processes of production.

Having thus described a practical and convenient embodiment of myinvention, I

claim as new and desire ters Patentz' 1. A device of the characterdescribed comprising two crossed members provided with jaw portions andhandle portions, each jaw portion having recesses in its sidesregistering with corresponding recesses in the other jaw,links extendingtransversely of the jaw portions and filling the recesses, pivot pinsconnecting the ends of the links with the respective members, and meansloosely retained in position between the crossed members, by the links,for preventto secure by Leting substantial relative longitudinalmovement of the crossed members.

2. A device of the character described comprising two crossed membersprovided with jaw portions and handle portions, links extendingtransversely of the jaw portions, pivot pins connecting the ends of thelinks with the respective jaw portions, and a roller loosely retained inposition between the crossed members by the links, said jaw membershaving curved recesses to receive said roller, whereby substantiallyrelative longitudinal movement bers is prevented.

In testimony whereof I affix my signature.

HEN RY V. SMITH.

of the crossed mem-

